Cribsheet

1. Trust the data, not anecdotes, when making parenting decisions

Anecdote is not data.

Evidence-based parenting. Throughout the book, Oster emphasizes the importance of relying on scientific evidence rather than anecdotes or popular wisdom when making parenting decisions. She encourages parents to:

• Look for high-quality studies, particularly randomized controlled trials
• Consider sample sizes and study designs when evaluating research
• Be cautious of correlations that may not indicate causation
• Recognize the limitations of available data and adjust expectations accordingly

By approaching parenting choices with a data-driven mindset, parents can make more informed decisions and feel more confident in their choices. However, Oster also acknowledges that personal preferences and family circumstances play a crucial role in decision-making, and data should be just one factor in the process.

2. Sleep training is effective and does not harm your child

There is no evidence of long- or short-term harm to infants; if anything, there may be some evidence of short-term benefits.

Safe and beneficial. Sleep training, including "cry it out" methods, has been shown to be effective in improving infant sleep without causing long-term harm. Key points include:

• Multiple studies show improved sleep duration and quality for sleep-trained infants
• No evidence of negative impacts on infant attachment or emotional development
• Potential benefits for maternal mental health and family functioning

Oster emphasizes that while sleep training can be emotionally challenging for parents, the data supports its use as a safe and effective tool for improving sleep. She recommends choosing a method that parents feel comfortable with and can consistently implement. The book also notes that sleep training is not necessary for all families and that parents should make choices based on their individual circumstances and preferences.

3. Breastfeeding has some benefits, but formula is a valid alternative

Breastfeeding doesn't guarantee later success—even at four—and late talkers mostly look like everyone else within a few years.

Balanced perspective. While breastfeeding offers some advantages, particularly in early infancy, the long-term benefits are often overstated. Key points:

• Short-term benefits: reduced risk of gastrointestinal infections and eczema
• Limited evidence for long-term impacts on obesity, IQ, or other outcomes
• Formula-fed babies can thrive and develop normally

Oster encourages parents to make feeding choices based on their individual circumstances and preferences, rather than feeling pressured by societal expectations. She emphasizes that the most important factor is ensuring the baby is well-nourished, whether through breast milk or formula. The book also addresses common breastfeeding challenges and provides practical advice for mothers who choose to breastfeed.

4. Vaccines are safe and crucial for protecting children's health

Vaccines prevent disease, suffering, and death.

Overwhelming evidence. The book presents a comprehensive review of vaccine safety and efficacy, addressing common concerns and misconceptions. Key points:

• Extensive research shows vaccines are safe and do not cause autism
• Vaccines have dramatically reduced the incidence of many dangerous diseases
• Risks of vaccine-preventable diseases far outweigh any potential vaccine side effects

Oster breaks down the evidence supporting vaccine safety, including large-scale studies and long-term follow-up data. She also explains herd immunity and the importance of maintaining high vaccination rates to protect vulnerable individuals. The book encourages parents to follow recommended vaccination schedules and to discuss any concerns with their healthcare providers.

5. Childcare choices should prioritize quality interactions, not philosophies

A high-quality day care is likely to be better than a low-quality nanny, and vice versa.

Focus on quality. When choosing childcare, the most important factor is the quality of interactions between caregivers and children, rather than adherence to a specific philosophy. Key considerations:

• Responsive, engaged caregivers who interact positively with children
• Safe, stimulating environment with age-appropriate activities
• Consistent routines and clear communication with parents

Oster reviews the evidence on different childcare options, including daycare centers, home-based care, and nannies. She emphasizes that high-quality care can be found in various settings and that parents should prioritize finding a good fit for their family's needs and values. The book also addresses common concerns about childcare, such as illness exposure and attachment issues.

6. Potty training timing varies, but consistency is key

Everyone does eventually use the toilet.

Flexible approach. The book presents a balanced view of potty training, acknowledging that there is no one-size-fits-all approach. Key points:

• Average age for potty training has increased over time
• No evidence that earlier training leads to better outcomes
• Consistency and positive reinforcement are more important than specific methods

Oster reviews various potty training approaches and their effectiveness, noting that most children will eventually learn regardless of the method used. She encourages parents to choose a strategy that fits their family's lifestyle and their child's readiness. The book also addresses common challenges, such as regression and nighttime training.

7. Discipline strategies should focus on consistency and avoiding anger

Parental anger is the first central part of the intervention.

Effective discipline. The book emphasizes evidence-based approaches to discipline that prioritize consistency and emotional regulation. Key strategies:

• Clear, consistent consequences for misbehavior
• Avoiding parental anger and emotional reactions
• Positive reinforcement for good behavior
• Age-appropriate expectations and communication

Oster reviews several evidence-based discipline programs, such as 1-2-3 Magic and the Incredible Years. She emphasizes the importance of parents managing their own emotions and maintaining consistency in their approach. The book also addresses common discipline challenges and provides practical tips for implementing effective strategies.

8. Early academic skills are less crucial than play-based learning for toddlers

There is no reason to do this, given the evidence on vaccine safety that I outlined earlier, and in fact, the risk of a febrile seizure actually increases if the MMR vaccine is given later.

Prioritize play. The book challenges the notion that early academic instruction is necessary or beneficial for young children. Key points:

• Limited evidence for long-term benefits of early academic skills
• Play-based learning supports cognitive, social, and emotional development
• Reading to children is beneficial, but formal reading instruction can wait

Oster reviews the research on early childhood education and finds little support for pushing academic skills at young ages. She encourages parents to focus on providing a rich, stimulating environment with plenty of opportunities for play and exploration. The book also addresses common concerns about school readiness and provides guidance on choosing preschool programs.

9. Physical and language milestones have wide normal ranges

There is tremendous variability across children, which you mostly cannot control.

Embrace variation. The book emphasizes that there is a wide range of normal development for both physical and language milestones. Key points:

• Milestone timing varies significantly among children
• Early or late achievement of milestones rarely predicts long-term outcomes
• Focus on overall progress rather than specific age-based expectations

Oster reviews the data on various developmental milestones, such as walking, talking, and fine motor skills. She encourages parents to avoid comparing their children to others and to focus on their individual progress. The book also provides guidance on when to seek professional evaluation for potential developmental delays.

10. Parental self-care is essential for family well-being

Being a good parent isn't about completely subsuming your entire personhood into your children.

Balance is key. The book emphasizes the importance of parents taking care of their own physical and emotional needs. Key points:

• Parental well-being directly impacts child outcomes
• Self-care is not selfish, but necessary for effective parenting
• Maintaining adult relationships and interests benefits the whole family

Oster encourages parents to prioritize their own sleep, mental health, and relationships. She addresses common sources of parental stress and guilt, providing strategies for maintaining balance and perspective. The book also emphasizes the importance of teamwork between partners and seeking support when needed.

Last updated: January 22, 2025